Production of halide free hydrocarbons

Abstract

A process and a process plant for efficient separation of ammonium halides from hydrocarbons is disclosed. The process involves high pressure gas/liquid separation and separate low pressure purification of the two streams, optionally in strippers.

1 . A process for conversion of a hydrocarbonaceous feed comprising at least 10 ppm wt  and less than 10000 ppm wt  of one or more halides, and at least 20 ppm wt  and less than 100000 ppm wt  organically bound nitrogen, to a hydrocarbon product stream by hydrotreatment, under effective hydrotreatment conditions, in the presence of a material catalytically active in hydrotreatment and an amount of hydrogen, wherein said conversion provides a mixed product stream comprises an amount of inorganic halides and an amount of ammonia,
 said process comprising the steps of   separating in a first separation step at a first pressure and at a first separation temperature the mixed product stream to provide an overhead stream and a bottoms stream,   combining the overhead stream with an amount of wash water,   separating, in a second separation step at a second pressure and at a second temperature, the combined overhead stream and wash water into a non-polar stream of hydrocarbon condensate product, a polar stream of wash water comprising ammonium halides and a gas stream rich in hydrogen,   in a third separation step at a third pressure and at a third temperature, separating the bottoms stream in a liquid hydrocarbon and a first gas phase stream,   in a fourth separation step at a fourth pressure and at a fourth temperature, separating the hydrocarbon condensate product into a purified hydrocarbon condensate and a second gas phase stream,   wherein the first separation temperature being above the precipitation temperature with respect to ammonium halides in the mixed product stream,   the second pressure being at least 80% of said first pressure,   the third pressure being below 50% of said first pressure, and   the fourth pressure being from 10% below to 10% above said third pressure.   
     
     
         2 . A process according to  claim 1 , wherein said hydrocarbonaceous feed comprises at least 100 ppmwt and less than 5000 ppmwt of one or more halides, and at least 100 ppmwt and less than 10000 ppmwt organically bound nitrogen. 
     
     
         3 . A process according to  claim 1 , wherein one or both of the first gas phase stream and the second gas phase stream is combined with an amount of wash water as a combined overhead stream and in a fifth separation step at a fifth pressure and a fifth temperature the combined overhead stream is separated in a gas phase stream, a non-polar stream of overhead condensate product and a polar stream of wash water comprising ammonium halides. 
     
     
         4 . A process according to  claim 1 , wherein one or both of said third separation step and said fourth separation step are a stripping process employing a stripping medium. 
     
     
         5 . A process according to  claim 4 , wherein said third separation step employs steam as a stripping medium. 
     
     
         6 . A process according to  claim 4 , wherein said fourth separation step is a reboiled stripping process, wherein heating for reboiling is provided by electrical heating, by heat exchange with steam or by heat exchange with a hot process stream. 
     
     
         7 . A process according to  claim 1 , wherein the temperature of said first separation step is above 220° C. and below 400° C. 
     
     
         8 . A process according to  claim 1 , wherein the temperature of said first separation step is below the temperature at which 5 wt % of the mixed product stream boils. 
     
     
         9 . A process according to  claim 1 , wherein at least an amount of the hydrocarbonaceous feed originates from a mixture rich in plastic, lignin, straw, lignocellulosic biomass, halide contaminated waste oils, aquatic biological material or sewage sludge. 
     
     
         10 . A process for conversion of a raw feed stream rich in molecules comprising C, H, N and one or more halides, and optionally O, S, Si, and other elements, said process comprising
 a step of thermal decomposition of said raw feed stream, to provide a precursor to a hydrocarbonaceous feed or a hydrocarbonaceous feed,   optionally a step of pre-treatment, purifying the precursor to hydrocarbonaceous feed to provide the hydrocarbonaceous feed, and   a hydrotreatment step for converting the hydrocarbonaceous feed in the presence of hydrogen, in accordance with  any of the previous claims , to provide a hydrocarbon product stream.   
     
     
         11 . A process according to  claim 10 , wherein the at least an amount of raw feed stream or the hydrocarbonaceous stream originates from a mixture rich in plastic, lignin, straw, lignocellulosic biomass, halide contaminated waste oils, aquatic biological material or sewage sludge. 
     
     
         12 . A process according to  claim 1 , followed by the step of directing the hydrocarbon product to a steam-cracking process. 
     
     
         13 . A system for hydrotreatment of a hydrocarbonaceous stream comprising
 a hydrotreatment reactor containing a material catalytically active in hydrotreatment, said hydrotreatment reactor comprising an inlet for introducing a hydrogen enriched hydrocarbon stream and an outlet for withdrawing a first hydrocarbon product stream,   a first means of separation having at least an inlet, an overhead outlet and a bottoms outlet,   a first means of mixing having two inlets and an outlet,   a second means of separation, having an inlet and a liquid polar phase outlet, a liquid non-polar phase outlet and a gas phase outlet,   a third means of separation having at least an inlet, an overhead outlet and a bottoms outlet,   a fourth means of separation, having an inlet, a liquid outlet and a gas phase outlet,   wherein said outlet for withdrawing a first product stream is in fluid communication with the inlet of said first means of separation,   wherein said overhead outlet is in fluid communication with the inlet of said first inlet of the first means of mixing,   wherein a source of water is in fluid communication with the second inlet of the first means of mixing,   wherein the outlet of the first means of mixing is in fluid communication with the inlet of the second means of separation,   wherein the liquid outlet of the first means of separation is in fluid communication with the inlet of said third means of separation,   wherein the liquid non-polar phase outlet of the second means of separation is in fluid communication with the inlet of said fourth means of separation,   and wherein one or more of the liquid outlets of said third or fourth means of separation are individually or collectively in fluid connection with one or more product outlets.   
     
     
         14 . A system for hydrotreatment of a hydrocarbonaceous stream according to  claim 13 , where one or both of said third and fourth means of separation is a stripper further having a stripping medium inlet optionally being in fluid communication with a steam inlet or a reboiler in thermal communication with a hot process stream, steam or a further source of heat. 
     
     
         15 . A system for hydrotreatment of a hydrocarbonaceous stream according to  claim 13 , wherein one of the third means of separation and the fourth means of separation are positioned above the other.